A HotSpot is a public place in which an access point provides wireless broadband network services to wireless-equipped visitors through a WLAN. HotSpots are often found in restaurants, hotels, and airports and may be free or charge a fee.

A FreeNetwork is defined by what its users can do with it, rather than the particular technology it is built on.

You can use a WiFi signal sniffer like the Linksys WUSBF54G Wi-Fi Finder to see if there are any signals nearby before using your laptop to connect.
Many locations restrict the free access to guests only. Some locations may have free WiFi access in common areas like lobbies, restaurants and meeting rooms that may be available to non-guests as well. Some signals can even be picked up from the parking lot.

Wireless hotspots may not provide any security. Many HotSpots leave all security turned off to make it easier to access the wireless network.
If security is important to you consider using VPN (encrypting and decrypting the data and sometimes the originating and receiving network addresses)
to connect back to your office. Go here for free Internet VPN. If you do not have access to a VPN and security is important,
you may want to limit your wireless network use in these areas to non-critical e-mail and basic Internet surfing.

If you need wireless connections on a regular basis from locations where there aren't any free ones,
you may want to subscribe to a Wi-Fi service. Some Wi-Fi providers worth considering:

T-Mobile

Boingo Wireless

iPass

Verizon

WayPort

User-generated Wi-Fi hotspots Easy Wifi from Devicescape is building a world Wi-Fi map from its users connections. The program picks up whatever networks its anonymous users are finding and classifies them according to signal strengths, provider and whether they are free and unlocked. You can add your own personal networks, which can be your own home Wi-Fi network, a friend's network, or even a small business network. This is much simpler than programming your devices with complicated security pass codes and other networking parameters (Use the Add Home Network page to do this). If users log onto an open home or office network with the app and don’t want it to show up on a map for everyone to use, Devicescape says it will remove networks from its database on request.

WIFI Liberater Toolkit is a tactical toolkit to liberate pay-per use wireless networks.
Wifi Liberator is an open-source toolkit for a laptop computer that enables its user to "liberate" pay-per-use wireless networks and create a free, open node that anyone can connect to for Internet access.

Easy WiFi Radar helps you find and connect to open wireless access points with a single mouseclick.
Just run it and it will connect you for FREE to the internet. Get your mail and browse the web without being charged. It doesn't get easier than this.

Evil Twins

"Evil twins
are wireless networks that pretend to offer trusty Wi-Fi
connections to the Internet like those available at some coffee shops, hotels
and conferences. On a laptop screen, an evil-twin Wi-Fi hotspot can look
identical to one of the tens of thousands of legitimate public networks that
consumers log on to every day, sometimes even copying the sign-in page. But
that's just a front, and fraudsters who set up the connections attempt to
capture any passwords or credit-card numbers that consumers using the link may
type."

"Evil twin networks are so easy to set up, requiring little more than a
laptop computer equipped with a Wi-Fi card. With a second Wi-Fi card, hackers
can also easily supply real wireless Internet service to unsuspecting users and
then comb through data from those people for passwords and other sensitive
information."

"To protect themselves, consumers should turn a laptop's Wi-Fi function off
when not in use to avoid accidentally connecting to an evil twin, security
experts recommend. Some advise users to sign up for Wi-Fi services, such as the
T-Mobile networks available in many Starbucks coffee shops, from computers with
fixed-line Internet access so they don't have to send credit-card numbers over
a wireless connection. T-Mobile provides free connection software for laptops
that automatically checks a Wi-Fi network's digital ID certificate to make sure
it's legitimate."

Man in the Middle

The Man in the Middle attack routes you to a legitimate hot spot by way of a thief's computer.
This attack revolves around the attacker enticing computers to log into his/her computer which is set up as a soft AP (Access Point). Once this is done, the hacker connects to a real access point through another wireless card offering a steady flow of traffic through the transparent hacking computer to the real network.
The hacker can then sniff the traffic for user names, passwords, credit card numbers...etc.

Either way, the bad guys see whatever you type in and whatever you have in your shared files. The only sure way to avoid these attacks is to abstain from transmitting passwords, financial data, or other sensitive personal information via public wireless networks.